* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
    'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
    sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  background: #f9fafb;
  color: #111827;
}

.app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 3rem 2rem;
  text-align: center;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.header h1 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  letter-spacing: -0.025em;
}

.header p {
  font-size: 1.125rem;
  max-width: 800px;
  margin: 0 auto;
  opacity: 0.95;
  line-height: 1.6;
}

.timeline-container {
  flex: 1;
  padding: 3rem 2rem;
  max-width: 1400px;
  margin: 0 auto;
  width: 100%;
  background: white;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  border-radius: 8px;
  margin-top: 2rem;
}

.footer {
  background: #1f2937;
  color: #f3f4f6;
  padding: 3rem 2rem;
  margin-top: 3rem;
}

.feature-list {
  max-width: 1400px;
  margin: 0 auto 3rem;
}

.feature-list h3 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 2rem;
  text-align: center;
  color: white;
}

.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.feature {
  background: #374151;
  padding: 1.5rem;
  border-radius: 8px;
  transition: transform 0.2s, box-shadow 0.2s;
}

.feature:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.feature strong {
  display: block;
  font-size: 1.125rem;
  color: #60a5fa;
  margin-bottom: 0.5rem;
}

.feature p {
  color: #d1d5db;
  font-size: 0.95rem;
  line-height: 1.5;
}

.instructions {
  max-width: 1400px;
  margin: 0 auto 2rem;
  background: #374151;
  padding: 2rem;
  border-radius: 8px;
}

.instructions h4 {
  font-size: 1.25rem;
  margin-bottom: 1rem;
  color: white;
}

.instructions ul {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 0.75rem;
}

.instructions li {
  color: #d1d5db;
  font-size: 0.95rem;
  padding: 0.5rem;
  background: #4b5563;
  border-radius: 4px;
}

.links {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.links a {
  color: white;
  text-decoration: none;
  font-weight: 600;
  padding: 0.75rem 1.5rem;
  background: #3b82f6;
  border-radius: 6px;
  transition: background 0.2s, transform 0.2s;
  display: inline-block;
}

.links a:hover {
  background: #2563eb;
  transform: translateY(-2px);
}

@media (max-width: 768px) {
  .header h1 {
    font-size: 1.875rem;
  }

  .header p {
    font-size: 1rem;
  }

  .timeline-container {
    padding: 1.5rem 1rem;
    margin-top: 1rem;
  }

  .footer {
    padding: 2rem 1rem;
  }

  .features {
    grid-template-columns: 1fr;
  }

  .instructions ul {
    grid-template-columns: 1fr;
  }

  .links {
    flex-direction: column;
    align-items: stretch;
  }

  .links a {
    text-align: center;
  }
}

.timeline-container > div {
  min-height: 600px;
}
